Enhancement of low density lipoprotein binding to both low density lipoprotein receptor-positive and -negative cells by tetracycline antibiotics.
Some tetracycline (TC) antibiotics, including TC and anhydrotetracycline, have been found to enhance specific binding of low density lipoprotein (LDL) to both LDL receptor-positive and -negative cells at relatively higher concentrations. When incubated at 37 degrees C, the ability of LDL receptor-negative human fibroblasts to bind 125I-LDL was increased from < 2 to 45 ng/mg by 170 microM TC. In normal human fibroblasts and Hep G2 cells, 125I-LDL binding was elevated 1.4- to 2-fold by 113 microM TC. The 125I-LDL binding in the presence of TC was diminished by both heparin and EDTA. The enhancement by TC was not observed when 125I-LDL binding was assayed at 4 degrees C. TC enhanced LDL binding to paraformaldehyde-fixed Hep G2 cells, excluding LDL receptor induction in the mechanism. These results demonstrated that TC enhanced cellular LDL binding through a process not involving functional LDL receptors.
Miura
S
S
Department of Applied Biological Science, Tokyo Noko University, Japan.
Hasumi
K
K
Takayasu
R
R
Sugimoto
M
M
Endo
A
A
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002460:Cell Line; D002477:Cells / Q000187:drug effects* / Q000378:metabolism*; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008565:Membrane Proteins; D011971:Receptors, Immunologic / Q000378:metabolism; D011973:Receptors, LDL / Q000032:analysis* / Q000378:metabolism; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D013754:Tetracyclines
D000900:Anti-Bacterial Agents; D002614:Chelating Agents; D008077:Lipoproteins, LDL; D008565:Membrane Proteins; D011971:Receptors, Immunologic; D011973:Receptors, LDL; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D013754:Tetracyclines; D006493:Heparin; D004492:Edetic Acid